Vehicle drive system and method and idle reduction system and method

ABSTRACT

One embodiment relates to a hybrid vehicle drive system for a vehicle comprising a first prime mover, a first prime mover driven transmission, a rechargeable power source, and a PTO. The hybrid vehicle drive system further includes a hydraulic motor in direct or indirect mechanical communication with the PTO and an electric motor in direct or indirect mechanical communication with the hydraulic motor. The electric motor can provide power to the prime mover driven transmission and receive power from the prime mover driven transmission through the PTO. The hydraulic motor can provide power to the prime mover driven transmission and receive power from the prime mover driven transmission through the PTO.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application

is a continuation of U.S. patent application Ser. No. 12/130,888, filedMay 30, 2008, which claims the benefit of priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 60/979,755, filed Oct. 12,2007, and U.S. Provisional Application No. 61/014,406, filed Dec. 17,2007;

is a continuation-in-part of U.S. patent application Ser. No.12/217,407, filed Jul. 3, 2008, which claims the benefit of priorityunder 35 U.S.C. § 119(e) to U.S. Provisional Application No. 60/959,181,filed Jul. 12, 2007, and U.S. Provisional Application No. 61/126,118,filed May 1, 2008; and

is a continuation-in-part of U.S. patent application Ser. No.13/629,533, filed Sep. 27, 2012 which is a continuation-in-part ofPCT/US2009/066151, filed Nov. 30, 2009, which claims the benefit ofpriority to U.S. Provisional Application No. 61/177,240, filed May 11,2009, and U.S. Provisional Application No. 61/118,980, filed Dec. 1,2008, and U.S. Provisional Application No. 61/235,998, filed Aug. 21,2009, and U.S. Provisional Application No. 61/251,285, filed Oct. 13,2009;

each of the above references is incorporated herein by reference in itsentirety.

BACKGROUND

The present disclosure relates to vehicle drive systems. Moreparticularly, the present disclosure relates to hybrid vehicle drivesystems employing electric and hydraulic components.

Hybrid vehicle drive systems commonly employ at least two prime moversarranged in different configurations relative to a transmission. Oneknown configuration is found in so-called “series-parallel” hybrids.“Series-parallel” hybrids are arranged such that multiple prime moverscan power the drive shaft alone or in conjunction with one another.

In one known hybrid vehicle drive system, a first and second prime mover(e.g., an internal combustion engine and an electric motor/generator)are arranged in a parallel configuration and used to provide power to adrive shaft and a power take-off (PTO) shaft through a transmission. PTOshafts are generally used to drive auxiliary systems, accessories, orother machinery (e.g., pumps, mixers, barrels, winches, blowers, etc.).One limitation of this system is that the second prime mover istypically positioned between the first prime mover and the transmission,creating the need to reposition existing drive train components.

In another known hybrid vehicle drive system, a first prime mover (e.g.,an internal combustion engine) drives a PTO through a transmission. Asecond prime mover (e.g., electric motor/generator) has been coupleddirectly to the PTO. One limitation of this system is that while itallows the electric motor to provide power to a drive shaft through thePTO, it does not provide power to a hydraulic pump for operation ofvehicle mounted hydraulic components and equipment. The system also doesnot use a hydraulic motor/pump as the second prime mover. The systemalso does not allow a hydraulic motor/pump to be driven by either theinternal combustion engine or by the electric motor/generator, nor doesit allow the hydraulic motor/pump and electric motor/generator to besimultaneously driven by the engine. The system also does not use thehydraulic motor/pump and electric motor/generator to simultaneouslyprovide power to a drive shaft.

Hybrid systems used in larger trucks, greater than class 4, havetypically utilized two basic design configurations—a series design or aparallel design. Series design configurations typically use an internalcombustion engine (heat engine) or fuel cell with a generator to produceelectricity for both the battery pack and the electric motor. There istypically no direct mechanical power connection between the internalcombustion engine or fuel cell (hybrid power unit) and the wheels in anelectric series design. Series design hybrids often have the benefit ofhaving a no-idle system, including an engine-driven generator thatenables optimum performance, lacking a transmission (on some models),and accommodating a variety of options for mounting the engine and othercomponents. However, series design hybrids also generally include alarger, heavier battery; have a greater demand on the engine to maintainthe battery charge; and include inefficiencies due to the multipleenergy conversions. Parallel design configurations have a directmechanical connection between the internal combustion engine or fuelcell (hybrid power unit) and the wheels in addition to an electric orhydraulic motor to drive the wheels. Parallel design hybrids have thebenefit of being capable of increased power due to simultaneous use ofthe engine and electric motor, having a smaller engine with improvedfuel economy while avoiding compromised acceleration power, andincreasing efficiency by having minimal reduction or conversion or powerwhen the internal combustion engine is directly coupled to thedriveshaft. However, parallel design hybrids typically lack a no-idlesystem and may have non-optimal engine operation (e.g., low rpm or hightransient loads) under certain circumstances. Existing systems on trucksof class 4 or higher have traditionally not had a system that combinesthe benefits of a series system and a parallel system.

Therefore, a need exists for a hybrid vehicle drive system and method ofoperating a hybrid vehicle drive system that allows a drive shaft toreceive power from at least three components. There is also a need for ahybrid vehicle drive system that allows for the prevention of frictionand wear by disengaging unused components. There is a further need for ahybrid vehicle drive system that uses regenerative braking to storeenergy in at least two rechargeable energy sources. Still further, thereis a need for a PTO-based hybrid system. Further still, there is a needfor a hybrid system optimized for use with a hydraulic system of thevehicle.

The need for engine idle reduction systems and methods also exists.Sophisticated power train control systems and power management systemsrequired for the operation of a hybrid vehicle drive system can add costand complexity. Therefore there is a need for an idle reduction systemthat allows equipment to be powered by one pump. There is also a needfor a system that allows for quick recharging from three sources(vehicle engine, external power grid, APU). There is also a need for asystem that can provide power to the equipment from two sourcessimultaneously (vehicle engine and electric motor) during periods whenequipment power requirements exceed the output of only an electric motordriven pump.

There is a further need for a series/parallel design in which the systemcan operate using either series or parallel configurations dependingupon which is most advantageous given operating requirements.

SUMMARY

One embodiment relates to a vehicle drive system for a vehiclecomprising a first prime mover, a first prime mover driven transmission,a rechargeable energy source, and a PTO. The vehicle drive systemfurther comprises a hydraulic pump in direct or indirect mechanicalcommunication with the PTO and an electric motor in direct or indirectmechanical communication with the hydraulic pump. The hydraulic pump hasa through-shaft, and the electric motor is mounted on an end of thethrough-shaft. The electric motor can receive power from the first primemover driven transmission through the PTO, and the hydraulic pump canreceive power from the electric motor when the electric motor rotates.The electric motor uses power from the rechargeable energy source, orfrom the first prime mover driven transmission through the PTO torotate.

Another embodiment relates to a hybrid vehicle drive system for avehicle including a first prime mover, a first prime mover driventransmission, a rechargeable power source, and a PTO. The hybrid vehicledrive system further includes a hydraulic motor in direct or indirectmechanical communication with the PTO and an electric motor in direct orindirect mechanical communication with the hydraulic motor. The electricmotor can provide power to the prime mover driven transmission andreceive power from the prime mover driven transmission through the PTO.The hydraulic motor can provide power to the prime mover driventransmission and receive power from the prime mover driven transmissionthrough the PTO.

Another embodiment relates to a hybrid vehicle drive system for use witha first prime mover and a first transmission driven by the first primemover. The system comprises a second prime mover coupled to arechargeable energy source a component, and an accessory having thethrough-shaft. The first prime mover is configured to provide powerthrough the first transmission, and the component is configured tooperate the second prime mover via the through-shaft. The second primemover is mounted on the end of the through-shaft, and the accessory isoperable through the operation of the second prime mover. The accessoryis a hydraulic pump and is communicatively coupled to a secondrechargeable energy source.

Yet another embodiment relates to a hydraulic system used in a hybridvehicle of any type. The vehicle includes a first prime mover, a firstprime mover driven transmission, an electric motor, a first rechargeableenergy source, and a power take off. The electric motor is configured torecharge the first energy source or is powered by the first energysource. The first prime mover is configured to provide power through thefirst prime mover driven transmission and the component to operate theelectric motor. The hydraulic system comprises an accessory having athrough-shaft, and the accessory is configured to be coupled to thesecond prime mover via the through-shaft. The second prime mover ismounted on an end of the through-shaft. The accessory is configured tobe operated through the operation of the second prime mover, and theaccessory is also configured to selectively operate the second primemover.

Yet another embodiment relates to a method of operating a hybrid vehicledrive system. The hybrid vehicle drive system includes a prime mover, aprime mover driven transmission, a second prime mover, a PTO component,and a first energy source. The PTO can transfer power from the primemover driven transmission to the second prime mover. The first energysource can provide power to or be powered by the second prime mover. Themethod may comprise powering an accessory through the operation of thesecond prime mover, wherein the accessory is equipped with athrough-shaft, and the second prime mover is mounted on an end of thethrough-shaft.

Yet another embodiment relates to a hybrid drive system for a vehiclecomprising a first prime mover, a first prime mover driven transmission,a rechargeable energy source, and a PTO. The hybrid drive systemcomprises a first electric motor, a hydraulic pump, and a secondelectric motor. The first electric motor is coupled to the rechargeableenergy source. The hydraulic pump is in direct or indirect mechanicalcommunication with the first electric motor. The hydraulic pump furtherhas a through-shaft. The first electric motor is mounted on an end ofthe through-shaft. The second electric motor is in direct or indirectmechanical communication with the PTO, and the second electric motor canreceive power from the prime mover driven transmission through the PTO.The second electric motor can also charge the rechargeable energysource. The hydraulic pump can receive power from the first electricmotor, and the second electric motor has a higher horsepower rating thanthe first electric motor.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will be described with reference to the accompanyingdrawings, in which:

FIG. 1 is a general block diagram of a hybrid vehicle drive systemillustrating paths of possible power sources for the drive shaftaccording to an exemplary embodiment.

FIG. 2 is a general block diagram illustrating the operation of a hybridvehicle drive system using an auxiliary power unit, second prime moverand accessory components to operate equipment according to an exemplaryembodiment.

FIG. 3 is a general block diagram illustrating the operation of a hybridvehicle drive system with the addition of a second rechargeable energysource according to an exemplary embodiment.

FIG. 4 is a general block diagram illustrating the operation of a hybridvehicle drive system using a first prime mover providing power tosimultaneously charge a first rechargeable energy source and operateequipment according to an exemplary embodiment.

FIG. 5 is a general block diagram illustrating the operation of a hybridvehicle drive system using a first prime mover providing power tosimultaneously charge first and second rechargeable energy sourcesaccording to an exemplary embodiment.

FIG. 6 is a general block diagram illustrating the operation of a hybridvehicle drive system during regenerative braking according to anexemplary embodiment.

FIG. 7 is a general block diagram illustrating the operation of a hybridvehicle drive system simultaneously charging first and secondrechargeable energy sources during regenerative braking according to anexemplary embodiment.

FIG. 8 is a general block diagram of a hybrid vehicle drive systemillustrating the use of a transfer case instead of a power take-off fromthe transmission according to an exemplary embodiment.

FIG. 9 is a general block diagram of a hybrid vehicle drive systemillustrating the use of a second power take-off, a third prime mover,and a second accessory component.

FIG. 10 is a general block diagram of a hybrid vehicle drive systemillustrating the use of a second power take-off and an electric motoraccording to an exemplary embodiment.

FIG. 11 is a general block diagram of a hybrid vehicle drive systemillustrating the use of a second power take-off, a high horsepowermotor, and a capacitor according to an exemplary embodiment.

FIG. 12 is a general block diagram of a hybrid vehicle drive systemillustrating the use of a second accessory component, a high horsepowermotor, and a capacitor coupled to the first prime mover according to anexemplary embodiment.

FIG. 13 is a general block diagram of a hybrid vehicle drive systemincluding an accessory coupled to a power take-off and a second primemover coupled to the accessory according to an exemplary embodiment.

FIG. 14 is a general block diagram of a hybrid vehicle drive systemsimilar to the system of FIG. 13 that includes a clutch between theaccessory and the power take-off according to an exemplary embodiment.

FIG. 15 is a general block diagram of a hybrid vehicle drive systemsimilar to the system of FIG. 13 that includes a clutch between thefirst prime mover and the transmission according to an exemplaryembodiment.

FIG. 16 is a general block diagram of a hybrid vehicle drive systemincluding a second prime mover coupled to a PTO and an accessory coupledto a transfer case according to an exemplary embodiment.

FIG. 17 is a general block diagram of a fluid coupling connecting twoexemplary elements of a hybrid vehicle drive system according to anexemplary embodiment.

FIG. 18 is a general block diagram of a hybrid vehicle drive system thatincludes a multi-input/output drive coupled to first and second PTOsaccording to an exemplary embodiment.

FIG. 19 is a general block diagram of a hybrid vehicle drive system thatdoes not include hydraulic drive components and includes electric motorscoupled to each of two PTOs coupled to the first prime mover accordingto an exemplary embodiment.

FIG. 20 is a general block diagram of a hybrid vehicle drive system thatincludes a smaller electric motor as a third prime mover to power ahydraulic pump according to an exemplary embodiment.

FIG. 21 is a general block diagram of a hybrid vehicle drive system thatdoes not include hydraulic drive components and includes electric motorscoupled to each of two PTOs coupled to the first prime mover along withan electric motor coupled to the internal combustion engine to poweron-board accessories according to an exemplary embodiment.

FIG. 22 is a general block diagram of a hybrid vehicle drive system inseries mode operation in accordance with an exemplary embodiment.

FIG. 23 is a general block diagram of a hybrid vehicle drive system in aseries mode of operation in accordance with an exemplary embodiment.

FIG. 24 is a general block diagram of a hybrid vehicle drive system in aparallel mode of operation in accordance with an exemplary embodiment.

FIG. 25 is a general block diagram of a hybrid vehicle drive system in acruising mode in accordance with an exemplary embodiment.

FIG. 26 is a general block diagram of a hybrid vehicle drive system in acruising mode in accordance with an exemplary embodiment.

FIG. 27 is a general block diagram of a hybrid vehicle drive system whenthe vehicle is stationary in accordance with an exemplary embodiment.

FIG. 28 is a general block diagram of a hybrid vehicle drive system whenthe first prime mover is used to recharge the energy source inaccordance with an exemplary embodiment.

FIG. 29 is a general block diagram of a hybrid vehicle drive system whenthe first prime mover is used to recharge the energy source inaccordance with an exemplary embodiment.

DETAILED DESCRIPTION

Hybrid vehicle drive systems according to several possible embodimentsare presented. One feature of one exemplary embodiment of the hybridvehicle drive system is that a drive shaft can be powered singly or inany combination by a first prime mover, a second prime mover, and anaccessory. Preferred embodiments incorporate hydraulic systems into thehybrid vehicle drive system for optimal energy storage and usage. It isnoted that the term motor as used herein refers to a motor/generator ormotor/pump and is not limited to a device that performs only motoroperations.

Another feature of one exemplary embodiment of the system is that when apower take-off (PTO) configured to be engaged or disengaged while atransmission is moving is used, any unneeded drive system componentsother than a first prime mover can be entirely disconnected from thedrive train, reducing inefficiencies and wear in situations where thedifferent portions of the system do not need to interact, such as when adrive shaft is solely driven by the first prime mover, or when a vehicleusing the system is stationary and a second prime mover and accessoryare not being driven by the first prime mover. Similarly, an optionalclutch between the first prime mover and the transmission can be used toreduce inefficiencies during regenerative braking by removing the firstprime mover from the system when vehicle braking occurs.

Yet another feature of one exemplary embodiment of the system is thatthe accessory (e.g., hydraulic pump, pneumatic pump, electric motor,etc.) can be powered singly or in any combination by the first primemover, the second prime mover, energy from braking, or energy stored ina second rechargeable energy source (e.g., battery, ultra capacitor,hydraulic accumulator, etc.). The presence of a second rechargeableenergy source also can obviate the need for a complicated pump controlsystem when the accessory is a hydraulic pump. If the pump is a variablevolume displacement pump, further simplification is possible because aclutch may not be needed between the second prime mover and the pump.Other types of pumps can also be used. According to one exemplaryembodiment, with a clutch between the second prime mover and thehydraulic pump, the pump can be an inexpensive gear pump.

Yet another feature of one exemplary embodiment of the system is that afirst rechargeable energy source connected to the second prime mover canbe recharged in one or more modes. These modes include: the second primemover using power from the first prime mover; the second prime moverusing power from regenerative braking; the accessory, using energystored in the second rechargeable energy source to operate the secondprime mover; an auxiliary power unit connected to the first rechargeableenergy source; an engine alternator, when present (the alternator can beincreased in capacity to allow for this additional charge while drivingor idle); or from an external power source, such as being directlyplugged into an external power grid. The second prime mover can drawupon this power stored in the first rechargeable power source beforedaily operation of the vehicle (e.g., after overnight charging), whenthe vehicle is stopped, or in other situations. In such situations, thesecond prime mover would operate the accessory to pre-charge orpressurize the second rechargeable energy source before the energy isneeded, which would provide higher density power storage when the secondrechargeable power source is a hydraulic accumulator, among otheradvantages. A higher density energy storage device is intended toprovide more available power at low revolutions per minute (RPM)operation and an overall lower mass system.

Various additional aspects and advantages will become apparent to thoseskilled in the art from the following detailed description of theembodiments.

Referring to FIGS. 1-20, hybrid vehicle drive systems according toseveral exemplary embodiments are shown. Various features of theseembodiments can be employed in other embodiments described herein.

As shown in FIG. 1, an exemplary embodiment of a hybrid vehicle drivesystem 10 can be employed on any type of vehicle. According to oneembodiment, the vehicle can be any type of light, medium, or heavy dutytruck. In one preferred embodiment, the vehicle is a truck that employshydraulic systems such as a boom truck. Alternatively, the vehicle canbe any type of platform where hybrid systems are employed. The vehiclemay have a wide variety of axle configurations including, but notlimited to a 4×2, 4×4, or 6×6 configuration.

In one preferred embodiment, the vehicle is truck such as anInternational 4300 SBA 4×2 truck. According to one exemplary embodiment,the vehicle includes an IHC MaxxforceDT engine with an output of 255 HPand 660 lbs. of torque. The vehicle further includes an Allison3500_RDS_P automatic transmission. The vehicle has a front gross axleweight rating (GAWR) of 14,000/12,460 lbs, a rear GAWR of 19,000/12,920lbs., and a total GAWR of 33,000/25,480. The vehicle includes ahydraulic boom. The vehicle boom has a working height of approximately54.3 feet, a horizontal reach of 36.0 feet, an upper boom has anextension of approximately 145 inches. The lower boom may travel betweenapproximately 0 degrees and 87 degrees from horizontal. The upper boommay have a travel between approximately −20 degrees and 76 degrees fromhorizontal. According to an exemplary embodiment, the vehicle mayfurther include a hydraulic platform rotator, a hydraulic articulatingjib and winch (e.g., with a capacity of 1000 lbs.), a hydraulic jibextension, hydraulic tool outlets, an on-board power charger providing 5kW at 240 VAC, and electric air conditioning with a capacity of 5,000BTU. The above referenced power, boom, and types of components areexemplary only.

System 10 includes a first prime mover 20 (e.g., an internal combustionengine, such as a diesel fueled engine, etc.), a first prime moverdriven transmission 30, a component 40 (e.g., a power take-off (PTO), atransfer case, etc.), a second prime mover 50 (e.g., a motor, such as anelectric motor/generator, a hydraulic pump with a through-shaft, etc.),and an accessory 60 (e.g., a hydraulic pump, such as a variable volumedisplacement pump, etc.). In certain embodiments, accessory 60 can actas a third prime mover as described below. Transmission 30 ismechanically coupled to component 40. Component 40 is coupled to secondprime mover 50. Second prime mover 50 is coupled to accessory 60.According to one exemplary embodiment, second prime mover 50 is a 50 kWelectric motor. When acting as a generator (as shown in FIGS. 3 and 4),second prime mover 50 may generate 30 kW continuously or as much as 75kW at peak times. The above referenced power parameters are exemplaryonly. Second prime mover 50 may be further used to power variouson-board components such as compressors, water pumps, cement mixerdrums, etc.

In a preferred embodiment, accessory 60 is embodied as a hydraulic motorand includes a through-shaft 61 coupled to component 40 embodied as aPTO. The through-shaft 61 is also coupled to the shaft of the mover 50embodied as an electric motor. In another embodiment, electric motor ormover includes a through-shaft 61 that is coupled to the PTO and thepump.

According to one embodiment, system 10 also includes a firstrechargeable energy source 70 (e.g., a battery, a bank of batteries, afuel cell, a capacitive cell, or other energy storage device), anAuxiliary Power Unit (APU) 80 (e.g., an internal combustion engine,possibly fueled by an alternative low emission fuel (e.g., bio-mass,natural gas, hydrogen, or some other fuel with low emissions and lowcarbon output), and a generator, a fuel cell, etc.), a secondrechargeable energy source 90 (e.g. a hydraulic accumulator, ultracapacitor, etc.), and onboard or external equipment 100 (e.g.,hydraulically operated equipment, such as an aerial bucket, etc.). Firstrechargeable energy source 70 is coupled to second prime mover 50 andprovides power for the operation of second prime mover 50. Firstrechargeable (e.g., pressurized or rechargeable) energy source 70 mayinclude other auxiliary components (e.g., an inverter provided for an ACmotor, a DC-to-DC converter to charge a DC system, an inverter for powerexportation to a power grid or other equipment, controllers for motors,a charger, etc). APU 80 is coupled to first rechargeable energy source70 and provides power to first rechargeable energy source 70. Accordingto one exemplary embodiment, second renewable energy source 90 is ahydraulic system with a high pressure portion (e.g., an accumulator) anda low pressure component (e.g., a reservoir tank).

Second rechargeable energy source 90 is coupled to accessory 60 andprovides stored power for accessory 60. Onboard or external equipment100 can be coupled to accessory 60 or second rechargeable energy source90 and operate using power from either accessory 60 or secondrechargeable energy source 90. In one embodiment, onboard or externalequipment 100 is coupled through second rechargeable energy source 90 toaccessory 60. According to various exemplary embodiments, APU 80 mayalso provide power to both second renewable energy source 90 and firstrechargeable energy source 70 when high hydraulic loads are required.APU 80 and second renewable energy source 90 may both provide power tohydraulically operated equipment 100.

In one preferred embodiment, component 40 is a PTO designed to engage ordisengage while the transmission is moving via a clutch mechanism. ThePTO can be a street side or curb side PTO. Component 40 can bedisengaged from transmission 30 when first prime mover 20 exceeds themaximum operating RPM of any component connected through component 40.For example, component 40 can be disengaged if first prime mover 20exceeds the maximum operating RPM of accessory 60. Alternatively, allcomponents connected through component 40 can operate throughout the RPMrange of first prime mover 20, and component 40 can be engagedcontinuously. In a preferred embodiment, component 40 can be disengagedduring high speed steady driving conditions to reduce friction and wearon system 10.

Alternatively, transmission 30 may be modified to incorporate component40 and optionally incorporate second prime mover 50 directly intotransmission 30. Component 40, embodied as a PTO, may optionally includea PTO shaft extension. An example of a PTO shaft extension is describedin U.S. Pat. Nos. 6,263,749 and 6,499,548 both of which are incorporatedherein by reference. Component 40 can have a direct connection totransmission 30.

Component 40 may interface with transmission 30 in a way that there is adirect coupling between mover 20, component 40, and transmission 30.Alternatively, component 40 may interface with transmission 30 in a waythat the interface directly couples component 40 to the torque converterof transmission 30. The torque converter may be in mechanicalcommunication with mover 20, but rotating at a different speed or mayrotate at the same speed as mover 20 if it is locked up.

A clutch mechanism can be employed to properly engage and disengagecomponent 40. In another preferred embodiment, component 40 is a PTOthat has an internal clutch pack, such as a hot shift PTO. A hot shiftPTO can be used when frequent engagements of the PTO are required, oftenwith automatic transmissions. In one embodiment, second prime mover 50can be operated at the same RPM as first prime mover 20 prior to theengagement of component 40. This is intended to reduce wear on theclutch mechanism if component 40 has a 1:1 ratio of input speed tooutput speed. If other ratios for component 40 are used, the RPM offirst prime mover 20 or second prime mover 50 can be adjustedaccordingly prior to engagement to insure that input and output speedmatch the ratio of the component to reduce wear on the clutch mechanism.

While component 40 is engaged, second prime mover 50 can operate toprovide power to a drive shaft 32 via transmission 30.

In FIG. 1, first prime mover 20 provides power to drive shaft 32 throughtransmission 30. Second prime mover 50 provides additional oralternative power to drive shaft 32 through component 40 andtransmission 30. Drive shaft 32 provides power to two or more wheels 33used to provide forward and backward momentum to the vehicle. Forexample, second prime mover 50 can optionally provide the sole source ofpower to drive shaft 32. Alternatively, second prime mover 50 canprovide additional power to drive shaft 32 during vehicle acceleration.When providing power to drive shaft 32, second prime mover 50 canoperate using power from first rechargeable energy source 70. Accordingto the various exemplary embodiments of system 10, first rechargeableenergy source 70 can be charged or powered by second prime mover 50, APU80 or another suitable source (e.g., the vehicle alternator, the powergrid, etc.).

Optional APU 80 can be used to power first rechargeable energy source 70when the vehicle is driving up a grade, as well as other situations.This use is intended to improve vehicle performance, particularly whenthe power requirements of the vehicle exceed the power available fromfirst prime mover 20, first rechargeable energy source 70, and secondrechargeable energy source 90. The presence of APU 80 is intended toallow for a smaller first prime mover 20. In one embodiment, APU 80 isof a type that produces lower emissions than first prime mover 20. APU80 is intended to enable a vehicle using system 10 to meet variousanti-idle and emission regulations.

In one embodiment, system 10 is configured to automatically engage APU80 or first prime mover 20 through component 40 or accessory 60 tocharge first rechargeable energy source 70 when the stored energydecreases to a certain amount. The permissible reduction in storedenergy can be determined based upon a user selectable switch. The switchspecifies the method of recharging first rechargeable energy source 70from an external power grid.

In one embodiment, a user can select between 220-240V recharging,110-120V recharging, and no external power source available forrecharging. For the different voltages, the amount of power that can bereplenished over a certain period of time (e.g., when connected to anexternal power grid overnight) would be calculated. Beyond that amountof power usage, first prime mover 20, or APU 80 is engaged to charge orprovide power to first rechargeable energy source 70. If no externalpower source is available, first prime mover 20 or APU 80 can beautomatically engaged during regular finite periods, calculated tominimize idle time. In one embodiment, APU 80 and/or optionally firstrechargeable energy source 70 can provide power to an external powergrid 200, also known as vehicle to grid (V2G) power sharing. This isintended to provide low-emission power generation and/or reducerequirements to generate additional grid power during peak loads on thegrid.

In another embodiment, a user may only select between two settings, onesetting to select charging using a grid and the other setting to selectcharging without using an external power grid. The controller wouldmonitor state of charge of the batteries and control rechargingdifferently for each setting. If no external charging from a power gridis selected, system 10 may allow the state of charge of firstrechargeable energy source 70 (batteries) to drop to a threshold (as anexample 30%), then the controller would cause either first prime mover20 or the optional APU 80 to be engaged to charge batteries to apredetermined level (as an example 80%) to minimize the frequency thatfirst prime mover 20 or APU 80 must be started. Or different levels ofdischarge and recharging may be selected to minimized idle time. System10 may occasionally recharge batteries to 100% of charge to helpcondition the batteries. If the user selectable switch indicated system10 would be charged from an external power grid, the controller mayallow the state of charge of first renewable energy source to drop to athreshold (as an example 30%), then the controller would cause eitherfirst prime mover 20 or optional APU 80 to be engaged to chargebatteries to a predetermined level that is lower (as an example 50%).The lower level allows the external power grid to recharge a greateramount of first rechargeable energy source 70 when vehicle can beplugged in or charged by the external power grid, reducing the fuelconsumption of prime mover 70 or optional APU 80.

External power grid 200 allows first rechargeable energy source 70 to berecharged with a cleaner, lower cost power compared to recharging firstrechargeable energy source 70 with first prime mover 20. Power from anexternal power grid may be provided at a fraction of the cost of powerprovided from an internal combustion engine using diesel fuel. Accordingto one exemplary embodiment, first rechargeable energy source 70 can berecharged from an external power grid 200 in approximately 8 hours orless.

In one embodiment, second rechargeable energy source 90 is utilized, andprovides power to accessory 60. Additional or alternative power can beprovided to drive shaft 32 by accessory 60. For example, accessory 60can provide power to drive shaft 32 until second rechargeable energysource 90 is discharged. Alternatively, accessory 60 can provideadditional power to drive shaft 32 during vehicle acceleration.Accessory 60 provides power to drive shaft 32 through second prime mover50, component 40, and transmission 30. The combination of power providedto drive shaft 32 by second prime mover 50 and accessory 60 is intendedto allow for the use of a smaller first prime mover 20 which providesthe best use of stored energy and reduces the overall system mass. Inanother embodiment, accessory 60 only receives power from second primemover 50 or from first prime mover 20 through component and does notprovide power to drive shaft 32. Accessory 60 may power equipmentdirectly.

In one exemplary embodiment, an optional clutch can be coupled betweenfirst prime mover 50 and accessory 60 or between component 40 and secondprime mover 50. The clutch is disengaged when the vehicle is stationaryso second prime mover 50 can turn accessory 60 without unnecessarilydriving component 40.

A variety of control systems can be utilized to control the variouscomponents (clutches, motors, transmissions, etc.) in system 10.Electronic control systems, mechanical control systems, and hydrauliccontrol systems can be utilized. In addition, a controller can beprovided to indicate a request to operate an accessory or otherequipment. In one embodiment, a controller similar to the controller inU.S. Pat. No. 7,104,920 incorporated herein by reference can beutilized. Preferably, the controller is modified to communicate bypneumatics (e.g., air), a wireless channel, or fiber optics (e.g.,light) for boom applications and other applications where conductivityof the appliance is an issue.

The control system can utilize various input criteria to determine anddirect the amount of power required or to be stored, the input criteriacan input operator brake and acceleration pedals, accessoryrequirements, storage capacity, torque requirements, hydraulic pressure,vehicle speed, etc.

A control system may control the torque and power output of second primemover 50 and accessory 60 so that component 40, second prime mover 50and accessory 60 are operated within the allowable torque and powerlimitations of each item so that the sum of second prime mover 50 andaccessory 60 do not exceed component 40 or exceed capacity oftransmission 30, such as capacity of transmission power takeoff drivegear rating or exceed capacity of transmission maximum turbine torque onan automatic transmission. Optionally the controller may monitor andcontrol additional input torque from the prime mover, or input torque ofthe prime mover after multiplication by the torque converter, along withthat from other prime movers or accessories to ensure that the turbinetorque limit is not exceeded or other internal torque ratings ofcomponents within an automatic transmission or an autoshift manualtransmission, or a manual transmission. The torque and power output ofsecond prime mover 50 and accessory 60 may also be controlled using aninput from the driver and/or from a power train control system. If twocomponents are used as described in other embodiments, the torque andpower output of the second and third prime mover and optional accessoryor accessories may be controlled so that the transmission power takeoffdrive gear rating with two power takeoffs is not exceeded or that thecapacity of transmission maximum turbine torque on an automatictransmission, or other toque rating of an internal component within atransmission of different kind, such as an autoshift manual or manualtransmission is not exceeded.

According to other exemplary embodiments, a control system may be usedfor other purposes (e.g., coupling component 40 to transmission 30;monitoring the charge status of first rechargeable energy source 70 andsecond rechargeable energy source 90; monitoring and managing thethermal status of various components (e.g., prime movers, rechargeableenergy sources, electronics, etc.); operating first prime mover 20,second prime mover 50, and accessory 60 to replenish energy in firstrechargeable energy source 70 and second rechargeable energy source 90and/or supply power to equipment 100; operate APU 80 as needed; orcontrol other functions). Information on the status of the system, suchas operating efficiency, status of rechargeable energy sources, andcertain operator controls may be displayed or accessed by the driver.

Referring to FIG. 2, an exemplary operation of system 10 is shown.Component 40 is disengaged from transmission 30. APU 80 charges orprovides power to first rechargeable energy source 70 when necessary.APU 80 can include a generator powered by an internal combustion engine.The generator can be connected to first rechargeable energy source 70through a power converter, AC/DC power inverter or other chargingsystem. First rechargeable energy source 70 provides power to secondprime mover 50. The operation of second prime mover 50 operatesaccessory 60. Accessory 60 provides power to on-board or externalequipment 100. First rechargeable energy source 70 and/or APU 80 mayprovide all the power for system 10 when the vehicle is stationary andfirst prime mover 20 is turned off (e.g., in an idle reduction system).If second prime mover 50 is not coupled to drive shaft 32 and insteadprovides power to accessory 60 (e.g., in an idle reduction system),system 10 may include a simplified control and power management system.

According to another exemplary embodiment, component 40 may bemechanically coupled to and first prime mover 20 may be operatedperiodically to provide power to second prime mover 50 throughtransmission 30 and component 40. Second prime mover 50 recharges firstrechargeable energy source 70 and/or powers accessory 60. Accessory 60can recharge second rechargeable energy source 90 or operate otherequipment.

According to another exemplary embodiment, system 10 is configured as anidle reduction system that can provide power to vehicle loads such asHVAC, computers, entertainment systems, and equipment without the needto idle the engine continuously. Accordingly, system 10 uses an electricmotor (e.g., prime mover 50) to power a hydraulic pump (e.g., accessory60) for the operation of hydraulic equipment (e.g., aerial buckets,hydraulically powered compressors, etc.). Alternatively, the electricmotor may directly power a compressor. The electric motor can beconfigured to only operate when there is a demand for hydraulic flow orthe need to operate other mechanically coupled equipment to conserveenergy within first rechargeable energy source 70. The electric motorcan be activated by a controller that receives a signal sent throughfiber optics or a signal sent through other means.

In one embodiment, mover 20 is not engaged with component 40 when mover50 is used to power a pump or other mechanically coupled equipment 100.While component 40 (PTO) is not engaged, the PTO may be modified toallow shaft 32 to spin with low resistance. A PTO can be chosen with afeature that normally limits movement of the PTO when not engaged, thisfeature can be disabled when the electric motor is used to power thehydraulic pump. This concept also applies to “operating mode” for hybridsystem process below discusses with reference to FIGS. 3 and 4. Thistype of idle reduction can be used when the vehicle is stationary.

Batteries (e.g., rechargeable energy source 70) provide energy for theelectric motor. After the batteries are depleted, an external power gridis used to recharge the batteries.

If the rechargeable energy reserve is large enough, the electric motor(mover 50) may operate continuously, eliminating the need for acontroller to turn motor on and off based upon demand. Such a system maybe coupled to a variable volume displacement pump to reduce flow whendemand for hydraulic flow is low, resulting in lower consumption ofpower from the rechargeable energy source. This same method ofcontinuous operation can also be used for hybrid system configurations.

Depending upon the battery system, the batteries may be thermallycorrected during charging. Thermal correction may be needed if thetemperature of the battery exceeds a certain threshold. A coolingsystem, either external to the vehicle or internal to vehicle may beused, such that coolant is circulated to reduce heat or the battery casecan be ventilated with cooler air to dissipate heat, possibly with apowered ventilation system. A second pump may also be connected to a PTO(as shown in FIG. 9). First prime mover 20 may be started and used torecharge by engaging component 40 to transmission and operating secondprime mover 50 as a generator to recharge first rechargeable energysource batteries. If there is insufficient energy to operate theelectric motor driven hydraulic pump, the vehicle engine is started, PTOengaged and the second pump is used to power the equipment. Further, thesecond pump can be used when the hydraulic power requirements exceed thepower output of the electric motor coupled to the hydraulic pump.Alternatively, prime mover 50 could directly power the first accessory(hydraulic pump) and the second prime mover could be made not to operateas a generator. Not operating second prime mover as a generator mayreduce system complexity and reduce cost.

In another embodiment, first rechargeable energy source 70 providespower to electrical systems of the vehicle such as “hotel loads” (e.g.,HVAC, lighting, radio, various electronics, etc.). In yet anotherembodiment, first rechargeable energy source 70 charges a main crankbattery of the vehicle. The main crank battery can be isolated fromsystem 10. First rechargeable energy source 70 may also be used in otherconfigurations that use 100% electric propulsion for certain periods topower additional vehicle systems such as power steering, brakes andother systems normally powered by first prime mover 20.

In yet another embodiment, second prime mover 50 provides power toexternal devices directly or through an additional rechargeable energysource and an associated inverter. Utilizing second prime mover 50 topower external devices is intended to lessen the need for an additionalfirst prime mover 20 powered generator.

In yet another embodiment, a sophisticated control system (e.g., a pumpcontrol system utilizing fiber optics, etc.) can be used to control theoperation of accessory 60. In yet another embodiment, accessory 60 is avariable volume displacement pump. Accessory 60 can operatecontinuously, only providing flow if there is a demand. When no demandis present, accessory 60 provides little or no additional friction orresistance within the system.

Referring to FIG. 3, another exemplary operation of system 10 is shown.First rechargeable energy source 70 and/or APU 80 may provide power forsystem 10 when the vehicle is stationary and first prime mover 20 isturned off (e.g., in an idle reduction system). For example, as shown inFIG. 3, energy source 70 may power accessory 60. In one embodiment,second rechargeable energy source 90 is utilized. Accessory 60 storesenergy in second rechargeable energy source 90, as shown. Second primemover 50 is engaged to operate accessory 60 (e.g., a hydraulic pump)when the stored energy in second rechargeable energy source 90 (e.g., ahydraulic accumulator) is reduced to a predetermined level. Theutilization of second rechargeable energy source 90 is intended toreduce operation time of accessory 60. Accessory 60 only needs tooperate to maintain energy in second rechargeable energy source 90.On-board or external equipment 100 (e.g., any hydraulic equipment) ispowered by second rechargeable energy source 90. In one embodiment, aclutch mechanism is used to disengage accessory 60 from second primemover 50 during vehicle travel when second rechargeable energy source 90has been fully charged. This is intended to reduce friction on system 10when second prime mover 50 is needed, but accessory 60 is not. Secondrechargeable energy source 90 can provide hydraulic power to equipment100 at a constant system pressure through a pressure reducing valve.

Alternatively, second rechargeable energy source 90 and two hydraulicmotor/pump units are coupled together to provide constant systempressure and flow. The first unit (e.g., a hydraulic motor) receiveshigh pressure flow from second rechargeable energy source 90. The firstunit is coupled to a second unit (e.g., a pump) which supplies hydraulicpower to equipment 100 at a lower pressure. Both hydraulic secondrechargeable hydraulic circuit and low pressure hydraulic equipmentcircuit have a high pressure and a low pressure (reservoir or tank)sections. A control system may be utilized to maintain constant flow inthe low pressure hydraulic equipment circuit as the high pressure flowfrom the second rechargeable source (accumulator) reduces or varies. Theadvantage of this configuration is that the energy from the highpressure accumulator is more efficiently transferred to the equipment.This configuration also allows independent hydraulic circuits to be usedfor the propulsion system and for equipment 100. The independenthydraulic circuits allow for fluids with different characteristics to beused in each circuit. Further, a hydraulic circuit that may besusceptible to contamination (e.g., the equipment circuit) can be keptseparate from the other hydraulic circuit (e.g., the propulsioncircuit).

In another embodiment, second rechargeable energy source 90 is utilized,and accessory 60 is a hydraulic pump. Second rechargeable energy source90 can include a low pressure fluid reservoir and a hydraulicaccumulator. The utilization of second rechargeable energy source 90obviates the need for a sophisticated pump control system and theassociated fiber optics; instead a simpler hydraulic system can be used(e.g., an insulated aerial device with a closed center hydraulic systemand a conventional control system, etc.). If the speed of accessory 60slows due to depletion of on-board power sources, accessory 60 canoperate longer to maintain energy in second rechargeable energy source90. This is intended to minimize any negative effects on the operationof equipment 100. According to one exemplary embodiment, second primemover 50 is an AC motor and turns at generally a constant rateregardless of the output volume of accessory 60 (e.g., to create two ormore different levels of flow from accessory 60).

However, in some scenarios, second prime mover 50 may provide power toaccessory 60 and the speed of second prime mover 50 may be varied by acontroller. For example, the speed of second prime mover 50 may bevaried to reduce the flow of fluid from accessory 60 (e.g., for twospeed operation of an aerial device where lower hydraulic flow may bedesirable for fine movement of the boom).

In one embodiment, system 10 can provide the advantage of allowing avehicle to operate at a work site with fewer emissions and engine noiseby using an operating mode. In an operating mode (as shown in FIGS. 3and 4), first prime mover 20 (e.g., an internal combustion engine, suchas a diesel fueled engine, etc.) is turned off and component 40 (PTO) isdisengaged from transmission 30, and component 40 when disengaged isable to spin freely with little resistance, and power from firstrenewable energy source 70 and second renewable energy source 90 areused to operate on-board or external equipment 100 and electricalsystems of the vehicle such as “hotel loads” (e.g., HVAC, lighting,radio, various electronics, etc.). According to another exemplaryembodiment, second renewable energy source 90 may be optional and firstrenewable energy source 70 may directly power to equipment 100.According to one exemplary embodiment, first renewable energy source 70has a capacity of approximately 35 kWh and is configured to provideenough power to operate the vehicle for a full day or normal operation(e.g., 8 hours).

Referring to FIG. 4, yet another exemplary operation of system 10 isshown. When APU 80 is out of fuel, APU 80 is not used, or APU 80 is notpresent, first rechargeable energy source 70 can be recharged by othercomponents of system 10 (in addition to other methods). First primemover 20 and second prime mover 50 are preferably operated andsynchronized to the same speed (e.g., input and output mechanicalcommunication through component 40 is a one to one ratio). Component 40is preferably engaged to transmission 30. First prime mover 20 providespower to second prime mover 50 through transmission 30 and component 40.Adjustments to second prime mover 50 speed is made if the ratio betweenfirst prime mover 20 and second prime mover 50 is not one to one tominimize wear of the clutch in component 40 or to speed of first primemover 50. Operation of second prime mover 50 recharges firstrechargeable energy source 70 to a predetermined level of stored energy.This method of recharging first rechargeable energy source 70 isintended to allow continuous system operation in the field without theuse of external grid power. This method is further intended to allowcontinuous operation of equipment 100 during recharging of firstrechargeable energy source 70.

While charging first rechargeable energy source 70, second prime mover50 simultaneously operates accessory 60. Accessory 60 provides power toon-board or external equipment 100. After first rechargeable energysource 70 has been recharged, component 40 is disengaged fromtransmission 30. Operation of accessory 60 can continue without the useof first prime mover 20 as shown in FIG. 2. Alternatively, withcomponent 40 engaged, operation of accessory 60 can continue powered inpart or in full by prime mover 20. This may be useful for example, ifthere is a failure in one of the other components that power accessory60. This may also be useful if the power demand from accessory 60exceeds the power available from second prime mover 50. According to oneexemplary embodiment, first prime mover 20 provides supplementary powerto or all of the power to equipment 100 (e.g. a digger derrick that mayrequire higher hydraulic flow during digging operations). Using firstprime mover 20 to provide supplementary power to equipment 100 duringintermittent periods of high power requirement allows system 10 toinclude a smaller second prime mover 50 that is able to provide enoughpower for the majority of the equipment operation. The control systemmay receive a signal from the equipment indicating additional power isrequired beyond that provided by second prime mover 50. Such a signalmay be triggered by the operator, by activation of a function (e.g., anauger release, etc.), by demand in the circuit or component above apredetermined threshold, or by other means.

Referring to FIG. 5, yet another exemplary operation of system 10 isshown. Second rechargeable energy source 90 is utilized. Accessory 60provides power to second rechargeable energy source 90. In oneembodiment, on-board or external equipment 100 (e.g., hydrauliccylinders, valves, booms, etc.) is coupled to second rechargeable energysource 90, and can be powered by second rechargeable energy source 90.External equipment 100 may also be operated directly by accessory 60without the use of a second rechargeable energy source 90. This methodof recharging first rechargeable energy source 70 and secondrechargeable energy source 90 is intended to allow continuous systemoperation in the field without the use of external grid power. Thismethod is further intended to allow continuous operation of equipment100 during recharging of first rechargeable energy source 70 and secondrechargeable energy source 90.

Referring to FIG. 6, yet another exemplary operation of system 10 isshown. In one embodiment, a clutch or other mechanism is used todisengage first prime mover 20 from transmission 30 during vehiclebraking. This is intended to maximize the regenerative energy availablefrom vehicle braking. The forward momentum of the vehicle provides powerfrom wheels 33 to transmission 30. Transmission 30 may be reduced to alower gear to increase the RPMS and increase the amount of energytransferred to second prime mover 50. Second prime mover 50 can operateto charge first rechargeable energy source 70 and help slow the vehicleaccording to principles of regenerative braking Disengaging first primemover 20 from transmission 30 further reduces the amount of energytransferred back to first prime mover 20 during braking and reduces theneed for engine braking. The control system for the hybrid componentsmay also monitor chassis anti-lock brake system (ABS) activity. If thechassis anti-lock brake system has sensed possible wheel lock-up and hasbecome active, possibly due to low traction or slippery road conditions,then hybrid regenerative braking is suspended by the hybrid controlsystem. The regenerative braking system may be disabled as soon as ABSis active and may remain off for only as long as the ABS is active, oralternatively regenerative braking may remain off for a period of timeafter ABS is no longer active or regenerative braking may remain off forthe remainder of the ignition cycle to eliminate the chance thatregenerative braking could adversely affect vehicle handling in lowfriction, slippery road conditions during the current ignition cycle. Atthe next ignition cycle, regenerative braking may be reactivated.

Referring to FIG. 7, yet another exemplary operation of system 10 isshown. Second rechargeable energy source 90 is utilized. As mentionedabove, during vehicle braking, first rechargeable energy source 70 ischarged through operation of second prime mover 50. Accessory 60 canoperate to further slow the vehicle, and store energy in secondrechargeable energy source 90, if second rechargeable energy source 90is not fully charged. In this manner, regenerative braking can be usedto simultaneously charge multiple energy storage devices of system 10.This is intended to allow recharging of both energy storage devicesthrough braking during vehicle travel, among other advantages. A clutchcan be optionally included between first prime mover 20 and transmission30 to further improve regenerative braking.

Referring to FIG. 8, in an alternative embodiment of system 10,component 40 is a transfer case. Component 40 is coupled to transmission30, drive shaft 32, and second prime mover 50. Energy from regenerativebraking bypasses transmission 30, passing through component 40 tooperate second prime mover 50. Similarly, motive power for drive shaft32 from second prime mover 50 and accessory 60 bypasses transmission 30,passing through component 40. Component 40 further allows power fromsecond prime mover 50 to be transferred to drive shaft 32, assisting,for example, when the vehicle is accelerating. A conventional clutch canbe placed between drive shaft 32 and component 40 to disconnect driveshaft 32 when the vehicle is parked and to allow second prime mover 50to charge first rechargeable energy source 70 when transmission 30 iscoupled to component 40 and first prime mover 20 is coupled totransmission 30. An optional clutch can also be placed between component40 and transmission 30 or between transmission 30 and first prime mover20. This allows power from regenerative braking to be channeled directlyto second prime mover 50 and accessory 60.

In one embodiment, during operation of equipment 100, component 40 isnot coupled to second prime mover 50 and accessory 60 can optionallydirectly power equipment 100. An optional APU 80 can charge firstrechargeable energy source 70 and/or second rechargeable energy source90 as required.

Referring to FIG. 9, in an alternative embodiment of system 10, a secondcomponent 110 such as a power take-off (PTO) is coupled to thetransmission 30. Accessory 60 may be a hydraulic pump with thecapability to produce more power than a single power take-off cantransfer to transmission 30. First component 40 and second component 110are provided to cooperate to transfer more power from secondrechargeable energy source 90 to transmission 30 than a single componentis able to transfer. System 10 further includes a third prime mover 120(e.g., a motor, such as an electric motor/generator, etc.), and a secondaccessory 130 (e.g., a hydraulic pump, such as a variable volumedisplacement pump, etc.). Transmission 30 is mechanically coupled tocomponents 40 and 110. Second component 110 is coupled to third primemover 120. Third prime mover 120 is coupled to second accessory 130.First rechargeable energy source 70 is coupled to third prime mover 120and provides power for the operation of third prime mover 120. Secondrechargeable energy source 90 is coupled to second accessory 130 andprovides stored power for second accessory 130. While FIG. 9 shows asystem 10 with both third prime mover 120 and second accessory 130coupled to second component 110, according to other exemplaryembodiments, either third prime mover 120 or second accessory 130 may beabsent. If a clutch is provided between first prime mover 20 andtransmission 30, first component 40 and second component 110 may beconfigured to drive transmission 30, possibly without assistance fromprime mover 20 or when prime mover 20 is off. At slow speeds, iftransmission 30 includes a torque converter which is not locked, theoptional clutch may not be needed for components 40 and 110 to transferpower to transmission 30 and move the vehicle.

In an alternative embodiment of system 10 for FIG. 9, an external powergrid can be used with an electrical rechargeable energy source. Batterysize and system software can be modified to charge the battery in theelectric grid. For example, the software can be modified to use a chargedepleting mode if the battery is charged from the grid.

Referring to FIG. 10, in an alternative embodiment of system 10, a highhorsepower prime mover 140 (e.g., a motor such as a high output powerhydraulic motor, etc.) is coupled to second component 110. Highhorsepower prime mover 140 is further coupled to second rechargeableenergy source 90 (e.g., one or more accumulators). Second rechargeableenergy source 90 is pressurized by accessory 60 during highway speeds orwhile parked.

In one embodiment, high horsepower prime mover 140 receives power from aPTO to pressurize second rechargeable energy source 90 duringregenerative braking Conversely, mover 140 can aid acceleration of thevehicle through component 110 and transmission 30. A clutch can bedisposed between first prime mover 20 and transmission 30 for moreefficient regenerative braking. The embodiment of system 10 shown inFIG. 10 may include a system including second rechargeable energy source90 and two hydraulic motor/pump units that is configured to provideconstant system pressure and flow similar to the system described above.The first unit or high pressure motor is provided by high HP prime mover140. The second unit or low pressure pump (e.g., a variable displacementpump pressure compensated load sensing pump) may be provided betweenhigh HP prime mover 140 and second component 110 preferably with athrough-shaft or other means of mechanical communication. The equipmentcircuit can trigger operation of high HP prime mover 140.

Referring to FIG. 11, in an alternative embodiment of system 10, a highpower prime mover 140 is coupled to second component 110. Highhorsepower prime mover 140 is further coupled to an ultra capacitor 150(e.g., a fast charge and discharge capacitor, etc.) which may includemultiple capacitors. Capacitor 150 is in turn coupled to firstrechargeable energy source 70. First rechargeable energy source 70 ischarged by second prime mover 50 during highway speeds or while parked,by auxiliary power unit 80 or by being plugged into the electrical powergrid. High HP prime mover 140 may also independently recharge firstrechargeable energy source 70. In an optional charging scheme, APU 80 isoptional.

Referring to FIG. 12, in an alternative embodiment of system 10, asecond accessory 130 (e.g., a hydraulic pump, such as a variable volumedisplacement pump, etc.) and a high horsepower prime mover 140 (e.g., amotor such as a high power electric motor, etc.) are coupled to firstprime mover 20 (e. g., to the crankshaft of an internal combustionengine, such as a diesel fueled engine, etc.). Second accessory 130 andhigh horsepower prime mover 140 allow large amount of power to betransmitted to first prime mover 20. First rechargeable energy source 70is coupled to high horsepower prime mover 140 via capacitor 150 andprovides power for the operation of high horsepower prime mover 140.Second rechargeable energy source 90 is coupled to second accessory 130and provides stored power for second accessory 130. High horsepowerprime mover 140 may further be used to assist in cranking first primemover 20. Cranking first prime mover 20 may be particularly advantageouswhen first prime mover 20 is started and stopped frequently (e.g., toreduce idle time). High horsepower prime mover 140 may further be a morepowerful starter motor. While FIG. 9 shows a system 10 with both secondaccessory 130 coupled to second component 110 and high horsepower primemover 140, according to other exemplary embodiments, either secondaccessory 130 may be absent or horsepower prime mover 140 may be absent.

Referring to FIG. 13, in an alternative embodiment of system 10,includes a first prime mover 20 (e.g., an internal combustion engine,such as a diesel fueled engine, etc.), a first prime mover driventransmission 30, a component 40 (e.g., a power take-off (PTO), atransfer case, etc.), a second prime mover 50 (e.g., a motor, such as anelectric motor/generator, a hydraulic pump with a through-shaft, ahydraulic pump without a through-shaft with second prime mover 50 onlyconnected on one side etc.), and an accessory 60 (e.g., a hydraulicpump, such as a variable volume displacement pump, a hydraulic pump witha through-shaft etc.). Transmission 30 is mechanically coupled tocomponent 40. Component 40 is coupled to accessory 60. Accessory 60 iscoupled to second prime mover 50.

According to one exemplary embodiment, accessory 60 is a hydraulic pumpwith a through-shaft. Coupling the accessory 60 to the component 40provides several advantages. Hydraulic pumps with through-shafts aremore common and generally less expensive than through-shaft motors.Further, accessory 60 is generally smaller than second prime mover 50and allows for a more compact package when coupled to component 40.

Second rechargeable energy source 90 is coupled to accessory 60 andprovides stored power for accessory 60. Accessory 60 stores energy insecond rechargeable energy source 90 during the operation of system 10(e.g., during cruising or during regenerative braking, etc.). Accessory60 may draw energy from second rechargeable energy source 90 to providebursts of high horsepower to first prime mover 20 until secondrechargeable energy source 90 is exhausted. In another embodiment,accessory 60 may directly power equipment and second rechargeable energysource 90 may be absent.

Referring to FIG. 14, in an alternative embodiment, system 10 mayinclude a clutch 160 coupled to component 40. As described earliercomponent 40 may be a PTO with an integral clutch to selectivelydisconnect component 40 from first prime mover 20. However, even whendisconnected from first prime mover 20, component 40 may still bepowered by second prime mover 50 and/or accessory 60. The rotationalinertia of component 40 along with any associated frictional lossesrepresent power that is wasted in component 40. Optional clutch 160allows component 40 to be disengaged from second prime mover 50 and/oraccessory 60. Auxiliary Power Unit 80 is optional. Accessory 60 maydirectly power equipment 100. Source 90 is optional. Optional clutch 160could be used in other configurations where it would be advantageous tocompletely remove component 60 from second prime mover 80 or accessory60.

Referring to FIG. 15, in an alternative embodiment, system 10 mayinclude a clutch 165. System 10 as shown in FIG. 15 operates similar tothe embodiment of FIG. 10 and includes an accessory 60 (e.g., ahydraulic pump, such as a variable volume displacement pump, etc.)coupled to component 40. Similar to high horsepower prime mover 140shown in FIG. 10, accessory 60 may be configured to provide a largeamount of power to transmission 30 to augment first prime mover 10. Forexample, accessory 60 may transfer additional power to transmission 30to facilitate accelerating the vehicle. Accessory 60 may operate with orwithout an electrical motor as shown in FIG. 10.

Clutch 165 is coupled to first prime mover 20 and transmission 30.Clutch 165 is configured to selectively disengage first prime mover 20from transmission 30. The rotational inertia of first prime mover 20along with any associated frictional losses represent energy that iswasted in first prime mover 20 and reduces the efficiency ofregenerative braking in system 10. Disengaging first prime mover 20 fromthe rest of system 10 allows for more energy to be captured duringregenerative braking.

Referring to FIG. 16, in an alternative embodiment, system 10 mayinclude both a first component 40 such as a PTO, and a second component110 such as a transfer case coupled to transmission 30. Similar to theembodiment of FIG. 8, energy from regenerative braking bypassestransmission 30, passing through component 110 to operate accessory 60.Similarly, motive power for drive shaft 32 from accessory 60 bypassestransmission 30, passing through component. Component 110 further allowspower from accessory 60 to be transferred to drive shaft 32, assisting,for example, when the vehicle is accelerating. Transmission 30 isfurther mechanically coupled to component 40. Component 40 is coupled tosecond prime mover 50. Using both a PTO and a transfer case allowssystem 10 to benefit from better regenerative braking from drive shaftand the inclusion of a PTO to power electric motor operated hydraulicequipment. Second prime mover 50 may provide power to a second accessory65 to pressurize second rechargeable energy source 90 when the vehicleis parked or moving at a constant speed. Second rechargeable energysource 90 provides additional power during the acceleration of thevehicle. System 10 may optionally include a clutch between first primemover 20 and transmission 30 and/or between transmission 30 andcomponent 110.

As shown in FIG. 16, system 10 may further include a third component 180such as a PTO, a third prime mover 190, and a fourth prime mover 195.Third prime mover 190 is coupled to third component 180. Third primemover 190 is coupled to first rechargeable energy source 70 configuredto charge first rechargeable energy source 70. In this way, second primemover 50 may draw power from first rechargeable energy source 70 whilefirst rechargeable energy source 70 continues to be charged by thirdprime mover 190. Fourth prime mover 195 may be a larger starter motorand may be provided for first prime mover 20 to assist with low speedtorque and quick starts of first prime mover 20. The large starter motorcan also reduce unnecessary idle. First prime mover 20 may be startedand stopped to reduce unnecessary idling. Mover 195, mover 190, andcomponent 180 are optional. Clutches can be placed between mover 20 andtransmission 30 and between transmission 30 and component 110. Theinterface between mover 50 and accessory 65 can be by a one way or twoway interface.

Referring to FIG. 18, in an alternative embodiment, system 10 mayinclude both a first component 40 and a second component 110 such as aPTO coupled to transmission 30, and a third component 210 such asmulti-input/output drive coupled to first component 40 and secondcomponent 110. Third component 210 may be a hydraulic drive such asmanufactured by Funk Manufacturing Co. and distributed by Deere &Company. Third component is further coupled to a second prime mover 50.Second prime mover 50 may be an electric motor with the capability toproduce more power than a single power take-off can transfer totransmission 30. First component 40, second component 110, and thirdcomponent 210 are provided to cooperate to transfer more power fromsecond prime mover 50 to transmission 30 than a single component isable.

Referring to FIG. 19, in an alternative embodiment, system 10 mayinclude both a first component 40 and a second component 110 such as aPTO coupled to transmission 30. System 10 further includes a secondprime mover 50 (e.g., a motor, such as an electric motor/generator,etc.), and a third prime mover 220 (e.g., a motor, such as an electricmotor/generator, etc.), coupled to first component 40 and a secondcomponent 110, respectively. A first rechargeable energy source 70 iscoupled to second prime mover 50 and third prime mover 220 and providespower for the operation of second prime mover 50 and a third prime mover220.

Clutch 165 can disengage first prime mover 30, allowing the vehicle tobe driven in an all electric mode if other vehicle systems (e.g., HVACsystem, braking, power steering, etc.) are also electrically driven. Theall electric mode may also be possible in other system configurations(as shown in FIG. 6). The all electric mode saves fuel by allowing firstprime mover 20 to be off when not needed such as at low speeds or whenthe vehicle is stopped.

Optionally, transmission 30 may be constructed such that independentcomponent input/output gears are used, one for each component 40 and110. A clutch located in transmission 30 and in between input/outputgears for component 40 and 110 could allow series/parallel operation byoperating first prime mover 20, engaging clutch 165 and driving one ofthe component input/output gears causing either second prime mover 50 orthird prime mover 220 to act as a generator. The clutch in transmission30 disengages the other component input/output gear from the otherinput/output gear coupled to component 40, 110 that interfaces withprime mover 50 that acts as a generator. The remaining componentinput/output gear is coupled to the other gears in transmission 30 thattransmit power to drive shaft 32, possibly through another clutchinternal to the transmission that is engaged. The remaining prime moveracts as a motor and powers transmission 30 through the component that ismechanically coupled to the input/output gear. Such an arrangement isparticularly useful when the vehicle is driven in the city. In such asituation, prime mover 20 may operate at a more efficient speed andpower range, independent of vehicle speed, or prime mover 20 may beturned off completely to further reduce fuel consumption. If more poweris needed, the disengaged prime mover may be synchronized in speed withthe disengaged prime mover or prime movers 20 and then also coupled totransmission 30 to provide the needed additional power. The engagedprime over or transmission, making adjustments in speed to adapt to theratio of the input to output gearing of the component (PTO).

Alternatively, an optional APU could charge first rechargeable energysource 70 while first prime mover 20 is kept off and the vehicle isoperated in a series hybrid configuration in which clutch 165 isdisengaged. The APU is preferably a low emissions power source using alow carbon fuel. Such a configuration would be useful in an urban arearequiring low emissions. As in the all-electric mode, vehicle systems(e.g., HVAC, braking, power steering, etc.) are operated electricallywhen first prime mover 20 is off and the vehicle is being driven.

Referring to FIG. 20, in an alternative embodiment, system 10 may besimilar to the embodiment shown in FIG. 1. However, second prime mover50 (e.g., a motor, such as an electric motor/generator, etc.) mayprovide more power than necessary to drive accessory 60 (e.g., ahydraulic pump, such as a variable volume displacement pump, etc.).Therefore, a third prime mover 230 such as a smaller electricmotor/generator is provided. Third prime mover 230 is coupled to firstrechargeable energy source 70 and provides power to accessory 60.According to one exemplary embodiment, third prime mover 230 is a 10-60hp electric motor, more preferably a 20-40 hp electric motor.

Referring to FIG. 21, in an alternative embodiment, system 10 may besimilar to the embodiment shown in FIG. 1. However, a fourth prime mover240 may be coupled to first prime mover 20 with a clutch 245 (e.g., tothe crankshaft of the internal combustion engine). The coupling may bedirect to the crankshaft or through a belt or through a shaft. Fourthprime mover 240 may be, for example, an electric motor that providespower to one or more accessories 250 such as a cooling fan for firstprime mover 20, power steering pumps, an HVAC system, brakes, etc.Alternatively, it may be an integrated starter generator, optionallycapable of regenerative braking.

System 10 as shown in FIG. 21, is able to function in several modes,depending on the needs of the vehicle. System 10 can be configured as acombination series/parallel hybrid. For example, in an all electricmode, first prime mover 20 may be turned off and clutch 165, disengagedprime movers 50 and 220 may provide the power to drive wheels 33. Movers50 and 220 can be attached to a hydraulic pump. In one embodiment,movers 50 and 120 can be integrated with a hydraulic pump as a singleunit sharing a shaft. According to one exemplary embodiment, each ofprime movers 50 and 120 are able to provide at least 100 hp so that 200hp of power are transmitted to transmission 30 to drive wheels 33. Ifthe vehicle requires more power to drive shaft 32, first prime mover 20may be turned on. The speed of the output from first prime mover 20 issynchronized to the desired RPMs. Clutch 165 is engaged to couple firstprime mover 20 to transmission 30 in addition to prime movers 50 and120. If the vehicle requires even more power to drive shaft 32, clutch245 may be engaged so that fourth prime mover 240 provides additionalpower to crankshaft of first prime mover 20. Fourth prime mover 240 maysimultaneously provide power to one or more accessories 250. Using primemovers 50, 220 and 240 to supplement the power driving wheels 33 allowsa smaller, more efficient first prime mover 20 to be used in system 10.

Fourth prime mover 240 can drive accessories 240 via belts and/orpulleys and/or shafts and/or gears can be mechanically coupled to firstprime mover 20 through clutch 245 via belts, shafts, gears and/orpulleys. Prime mover 240 can be an electric motor with a through-shaft.The through-shaft can drive belts and/or pulleys for accessories (e.g.,HVAC, fan, steering, pumps, brakes, etc.) Clutch 165 may be integratedwith the transmission (as in a manual transmission or in an auto-shifttransmission). In an automatic transmission utilizing a torqueconverter, clutch 165 may be in between the torque converter and the ICEor integrated into the transmission and placed between the torqueconverter and the input gear for the PTO (for those transmissions thatutilize a PTO input gear independent of the torque converter). Theintegration and/or location of clutch 165 as described may be used forother embodiments shown in other diagrams in which a clutch can beplaced in between the ICE and the transmission.

If first prime mover 20 is a relatively small internal combustionengine, it may not be able to provide all the power to drive wheels andregenerate rechargeable energy source 70. In such a case, clutch 165 isdisengaged and clutch 245 is engaged so that first prime mover 20 onlydrives accessories 250 and third prime mover 240 which, in turn, acts asa generator to charge rechargeable energy source 70. Prime movers 50,and 120 provide power to drive wheels 33. This arrangement allows firstprime mover 20 operate in a more efficient zone. Clutch 245 maydisconnect first prime mover 20 from fourth prime mover 240 and fourthprime mover 240 may provide power for accessories 250. To keep theengine block warm when first prime mover 20 is turned off, enginecoolant may be circulated through a heating element (not shown). The ICEcan then be turned off to eliminate fuel consumption and reduceemissions if first rechargeable energy source has enough energy to powerother prime movers. As with all hybrid mechanizations described, acontrol system would assess various inputs to the system and adjustoutput of various devices, for example monitoring factors such as,energy levels, power demand, torque, control inputs, speeds,temperatures and other factors to determine appropriate operation ofprime movers, activation of clutches and other devices for optimalefficiency and performance. The heated coolant would then be circulatedback to first prime mover 20. The heated coolant may also be used towarm rechargeable energy source 70 or other on-board batteries when theambient air is cold. The warmer for the engine block and/or batteriescould be used on other embodiments.

System 10 as illustrated in FIG. 21 advantageously can utilize aparallel hybrid configuration with assist from fourth prime mover 240(e.g., accessory electric motor), first prime mover 20 (ICE), secondprime mover 50, and third prime mover 220. The parallel nature of system10 allows maximum acceleration as power can be utilized from multiplesources. As discussed above, transmission 30 can include a clutch (e.g.internal or external clutch 165). To reduce clutch wear, components 40and 110 can be utilized to launch the vehicle and once the input shaftis close to or at the same speed as the engine drive shaft, the clutchcan be engaged to couple prime mover 20 to transmission 30. This methodcan also be used for other embodiments in which a clutch is used toengaged the prime mover with the transmission.

Alternatively, system 10 in FIG. 21 can be provided as only a single PTOsystem. The use of two PTOs allows more power to be provided totransmission 30.

Accordingly to another embodiment, system 10 of FIG. 21 can be arrangedso that a parallel hybrid configuration is assisted from mover 220 andmover 50 during acceleration. In an electric only acceleration mode,power can be provided through components 40 and 110 via motors 50 and220 with prime mover 20 off.

Fourth prime mover 240 can be a multitude of electric motors forpowering individual accessories. Clutch 245 and mover 240 can beconnected to the front or other locations of prime mover 20 and could beused in other configurations with reference to FIGS. 1-20.Advantageously, electric only acceleration can use standard drive traincomponents and does not produce emissions. The use of prime mover 240powered through source 70 for movers 220 and 50 reduces emissions.

According to another embodiment, system 10 as illustrated in FIG. 21 canalso be configured to provide series electric only acceleration. Mover20 is used to charge first rechargeable energy source 70 (e.g.,batteries) and is not directly coupled to transmission 30 or isdisconnected from transmission 30 via clutch 165. Mover 240 providespower to accessories 250. Advantageously, mover 20 can be configured tooperate at most efficient RPM and load. Preferably, motor 240, has athrough-shaft and can act as a generator while mover 20 powersaccessories. Such a system would have advantages in stop and go typeapplications where electric motors can store energy during braking andaccelerate vehicle without having to change the operating RPM of mover20.

According to another embodiment, system 10 as illustrated in FIG. 21 canalso be operated in a ICE only cruise mode. During steady driving (suchas highway driving), ICE prime mover (e.g., mover 20) may provide all ofthe power and electric motors (e.g., movers 220 and 50) may be uncoupled(disconnected via clutches) from the drive train to reduce unnecessaryfriction and parasitic loads. Such mode provides best constant power atcruising speeds. In such a mode, mover 20 can be directly coupled orcoupled through clutch 165 to transmission 30 to provide best efficiencywhen mover 20 (ICE) can operate at a steady state and in an efficientRPM and load range. All unnecessary hybrid components can bedisconnected during ICE only cruise mode, as well as any unnecessaryloads. When accelerating or braking, electric motors (or hydraulicmotors) may be temporarily engaged to provide additional propulsion orcapture brake energy for reuse resulting in higher operating efficiencyand lower fuel consumption.

According to yet another embodiment, system 10 as illustrated in FIG. 21can also be provided in a mode in which highway speed is maintained bymover 20 and hybrid components are temporarily engaged to accelerate orslow the vehicle. An ICE (mover 20) can be used for base cruise powerand one or more electric or hydraulic motors are engaged as needed foradditional acceleration or to slow the vehicle. After the vehicleresumes a steady highway cruise, components 110 and 40 (e.g., PTOs) canbe disengaged to remove unnecessary resistance of unneeded hybridcomponents. Advantageously, such a configuration allows a smallerhorsepower engine to be used in optimal range for maximum efficiency andreduces large swings required in outputs from mover 20 (e.g., the engineoperates less efficiently when required to provide power to providelarge transient loads or when power output is much higher or lower thanits optimal range).

According to an alternative embodiment, mover 50 can include a pump or apump can be placed in between mover 50 and first component 40. Inanother alternative, the hydraulic pump could be placed after or behindmover 50. In this embodiment, power from source 70 can be utilized todrive pump for hydraulic components using mover 50. Such configurationwould be advantageous when the vehicle is stationary as power from thebatteries (e.g., source 70) is utilized to operate electric motors andhydraulic pumps.

According to another embodiment, system 10 illustrated in FIG. 21 can beoperated in a mode in which mover 20 is operated and the rotationalspeed of the hydraulic pump is constant. Component 40 can be engaged sothat mover 20 drives the hydraulic pump and mover 50. If rotation ofmover 50 needs to vary due to changes in required hydraulic flow, aseparate PTO can be engaged and used to recharge batteries while otherelectric motors can operate independently to provide power to the pumpwith varying rotation speed. As discussed above, the hydraulic pump canbe placed between mover 50 and component 40 or behind mover 50. In anembodiment in which a second PTO is not available, the rotational speedof the pump can be kept constant and the output of the pump can bevaried to change flow to meet required hydraulic flow variations. Thisconfiguration is particularly advantageous in digger derrickapplications in which the speed of the auger must be changed byadjusting flow.

Referring to FIGS. 22-29, in an alternative embodiment, system 10 may besimilar to the embodiment shown in FIG. 21. However, a fifth prime mover260 with a clutch 255 may be provided between first prime mover 20 andclutch 165. Fifth prime mover 260 may act as a motor to power the drivetrain or as a generator to recharge first rechargeable energy source 70or provide electrical power to other components of system 10. System 10,as shown in FIGS. 22-29, may advantageously operate in a variety ofmodes.

FIG. 22 illustrates system 10 in a series mode of operation as thevehicle is accelerating. First prime mover 20 turns fifth prime mover260 which charges first rechargeable energy source 70. Clutch 165 isdisengaged to decouple fifth prime mover 260 from transmission 30. Firstrechargeable energy source 70 provides electrical power to second primemover 50 and third prime mover 220 which drive transmission 30 throughfirst component 40 and second component 110, respectively. According toother exemplary embodiments, only one of second prime mover 50 and thirdprime mover 220 may provide power to transmission 30.

FIG. 23 illustrates system 10 in a series mode of operation as thevehicle is accelerating according to another exemplary embodiment. Firstprime mover 20 turns fifth prime mover 260 which charges firstrechargeable energy source 70. Clutch 165 is disengaged to decouplefifth prime mover 260 from transmission 30. First rechargeable energysource 70 provides electrical power to second prime mover 50 and thirdprime mover 220 which drive transmission 30 through first component 40and second component 110, respectively. According to other exemplaryembodiments, only one of second prime mover 50 and third prime mover 220may provide power to transmission 30. Clutch 245 is engaged so firstprime mover 20 further drives fourth prime mover 240. Fourth prime mover240 may be used to power on-board accessories 250 and/or recharge firstrechargeable energy source 70.

FIG. 24 illustrates system 10 in a parallel mode of operation as thevehicle is accelerating. Power from both first prime mover 20 and firstrechargeable energy source 70 is used to power the drive train. Firstprime mover 20 turns fifth prime mover 260 and transmission 30. Clutch165 is engaged to couple fifth prime mover 260 to transmission 30. Firstrechargeable energy source 70 provides electrical power to second primemover 50 and third prime mover 220 which drive transmission 30 throughfirst component 40 and second component 110, respectively. According toother exemplary embodiments, only one of second prime mover 50 and thirdprime mover 220 may provide power to transmission 30. First rechargeableenergy source 70 further powers fourth prime mover 240. Clutch 255 isengaged so fourth prime mover 240 is coupled to first prime mover 20 toassist driving the drive train. To reduce clutch wear, clutch 165 may bedisengaged and second prime mover 50 and third prime mover 220 (viacomponents 40 and 110) may provide the initial power to accelerate thevehicle. This method may also reduce or eliminate the need for a torqueconverter. Once the input shaft is close to or the same speed as theengine drive shaft, clutch 165 is engaged to couple first prime mover 20and transmission 30.

FIG. 25 illustrates system 10 in a cruising mode with first prime mover20 providing the power to maintain a relatively constant speed for thevehicle (e.g., during highway driving). Unnecessary loads such as unusedhybrid components, are disconnected. Directly coupling first prime mover20 to drive shaft 32 provides best efficiency when first prime mover 20can operate at a steady state in an efficient rpm and load range.

As shown in FIG. 26, hybrid components of system 10 may be temporarilyengaged when vehicle is in a cruising mode (FIG. 25) to slow oraccelerate the vehicle. First rechargeable energy source 70 may provideadditional power to the drive train through one or more prime movers toaccelerate the vehicle. After vehicle resumes a steady highway cruise,the additional prime movers can be disengaged (e.g., by disengagingcomponents 40 and 110) to remove unnecessary resistance of unneededhybrid components. Temporarily using hybrid components to provideadditional power to the drive shaft allows a smaller horsepower engineto be used in its optimal range for maximum efficiency. Large swings inrequired output from the ICE are further reduced. Internal combustionengines generally operate less efficiently when required to providelarge transient loads or when power output is much higher or lower thanthe optimal range. As alternative embodiment, additional prime moversmay be engaged if needed to slow or accelerate the vehicle. For example,second prime mover 50 can be coupled to transmission 30 through firstcomponent 40 to provide additional acceleration or slow the vehicle.

To reduce idle time of the internal combustion engine, first prime mover20 may be turned off when the vehicle is stationary, as shown in FIG.27. Second prime mover 50 is powered by first rechargeable energy source70 and drives accessory 60 and equipment 100. According to otherexemplary embodiments, accessory 60 may be provided between firstcomponent 40 and second prime mover 50 (as shown in FIG. 13).

As shown in FIG. 28, first prime mover 20 may be used to recharge firstrechargeable energy source 70. According to one exemplary embodiment,accessory 60 is a hydraulic pump. If the rotational speed of secondprime mover 50 needs to vary (e.g., to accommodate changes in requiredhydraulic flow), component 110 is engaged and used to recharge firstrechargeable energy source 70 through third prime mover 220. Secondprime mover 50, meanwhile, can operate independently to provide power toaccessory 60 with varying rotation speed. First rechargeable energysource 70 may further provide power to fourth prime mover 240 to driveon-board accessories 250. According to another exemplary embodiment, ifthe rotational speed of the hydraulic pump is constant, component 40 maybe engaged so that first prime mover 20 drives accessory 60 and secondprime mover 50 without the intermediate recharging step. According tostill another exemplary embodiment, rotational speed of second primemover 50 may be varied and component 110 may be absent. The system maybe charged while varying flow by keeping the rotational speed ofaccessory 60 constant while varying the output of the pump to changeflow (e.g. on a digger derrick application in which the speed of theauger must be changed by adjusting flow).

As shown in FIG. 29, first prime mover 20 may be used to recharge firstrechargeable energy source 70. First prime mover 20 turns fifth primemover 260 which charges first rechargeable energy source 70. Clutch 165is disengaged to decouple fifth prime mover 260 from transmission 30.Second prime mover 50, meanwhile, can operate independently to providepower to accessory 60 with varying rotation speed. First rechargeableenergy source 70 may further provide power to fourth prime mover 240 todrive on-board accessories 250.

According to another exemplary embodiment, system 10 may be an idlereduction system. An idle reduction system may have a configurationsimilar to any previously described embodiment of system 10 but is notconfigured to provide power back to first prime mover 20 and drive shaft32 (e.g., the drive train). Instead, component 40 only provides power inone direction (e.g., component 40 does not back-drive into transmission30). Such a system 10 does not require additional software, calibrationand control electronics that is required for the integration of a hybriddrive system. Such a system 10 may also not require sophisticatedthermal management systems and higher capacity motors and driveelectronics. Such a system 10 may include an optional secondaryrechargeable power source 90 such as an accumulator and/or an optionalAPU 80 or may even include a connection to a power grid. Similar to theembodiment shown in FIG. 14, system 10 may include an optional clutch160 between component 40 and second prime mover 50 or accessory 60. Ifsystem 10 does not include a second rechargeable power source 90 such asan accumulator, system 10 may include air, wireless or fiber opticcontrols. If system 10 includes a second rechargeable power source 90,no additional control system is required (e.g., the accumulator forms aclosed centered hydraulic system with hydraulic controls).

As an example, in one idle reduction configuration, a PTO with anintegrated clutch is connected to a transmission and is coupled to ahydraulic motor. The hydraulic motor has a through-shaft and is alsocoupled to an electric motor. The motor may be an AC motor or a DCmotor. Batteries supply energy to the motor, electronics control motorspeed and turn motor on and off. The PTO may be disengaged from thetransmission to allow the electric motor to move the hydraulic pump. Itmay be necessary to modify the PTO to allow the shaft to spin freelywhen not engaged with the transmission. When the batteries reach a lowstate of charge, or the electric motor speed slows below an acceptablelevel due to low battery energy, the prime mover (usually a diesel orgas engine) is started. The engine rpm is adjusted so that the PTO shaftwill provide the needed rotational speed for the hydraulic pump. PTO isthen engaged and drives the hydraulic pump.

The batteries can be charged through the electric motor, or through avehicle alternator, or alternatively the batteries may remain depletedat the job-site and recharged once the vehicle returns to a location inwhich power from the grid can be used to recharge the batteries. Ifbatteries remain depleted, the engine is started, PTO is engaged andhydraulic pump or other auxiliary equipment often used on a work truckat a job-site is mechanically powered by the first prime mover (ICE).

The location to charge the vehicle may be a garage with a chargingstation or an ordinary plug. Using only grid power to recharge thebatteries can simplify the idle reduction system. A separate vehiclemonitoring system may record if the batteries are recharged at a garageovernight, or if the batteries need to be serviced or replaced. Such asystem may send a signal via a link (such as cellular, satellite, orwireless local area network, or a wired connection) to a fleetmanagement system so that fleet personnel can take action to maintainsystem or train vehicle operators.

The battery system may be designed to be modular and easy forreplacement battery modules to be installed. A modular, replaceablebattery system can allow a vehicle to use a lower cost battery initiallythat has a shorter useful life and then replace it when the existingbattery no longer can store sufficient energy, with the same type ofbattery, or a more advanced battery. A replaceable battery system may bebeneficial since lower cost batteries can be used until more advancedbatteries capable of more energy storage, lower mass and greater servicelife are available at lower costs. The battery system may haveelectronics integrated in a module and may include thermal management.The electronics may produce uniform input and output electricalcharacteristics, allowing for different battery technologies to be used,without affecting idle reduction performance. The battery may also bedesigned for quick replacement. Such a design could make it possible touse batteries that are charged at a base station. Batteries at a basestation may provide power for a facility or to the grid when not neededfor a vehicle. There may be additional electronics integrated with thebattery module including monitoring circuitry to record power available,power used, how much of the battery life has been reduced (possiblybased upon overall percent discharge, rate of discharge and recharge,average operating temperature, frequency of balancing various cells orfrequency of achieving full state of charge). Such a system may allowfor rental of a battery system or payment based upon battery usage andestimated reduction in battery useful life. This type of modular batterysystem can also be used on other embodiments of hybrid systems describedin this disclosure.

As has been discussed, system 10 may perform many different functions.The function of the various exemplary embodiments of system 10 maychange based on the behavior of the vehicle that includes system 10. Forexample, when the vehicle is braking, regenerative braking may be usedto recharge first rechargeable energy source 70 and/or secondrechargeable energy source 90. During acceleration, first rechargeableenergy source 70 and/or second rechargeable energy source 90 may be usedto provide power to the drive train. When the vehicle is parked,on-board equipment 100 such as a hydraulic lift may be activated. Such ahydraulic lift would draw power from second rechargeable energy source90 (e.g., a hydraulic accumulator) or be driven directly by an accessory60 such as a hydraulic pump. Once the lift is raised and stops,hydraulic fluid no longer flows. In this position, second rechargeableenergy source 90 does not have to be charged and accessory 60 does nothave to run to keep the hydraulic lift raised. Therefore, when the liftis not moving, second prime mover 50 may be turned off to reduceunnecessary consumption of energy from first rechargeable energy sourceand first prime mover 20 may be turned off to reduce unnecessary idling.Prime mover 20 may remain off when the vehicle is parked if there issufficient energy in rechargeable energy sources for equipment, or“hotel loads”, or power that is exported from the vehicle to power toolsor lights or other loads. System 10 may include sensors and a controlsystem to automatically turn on and off first prime mover 20, secondprime mover 50, accessory 60, or other components of system 10 when theyare not needed thereby conserving fuel and reducing emissions.

According to various exemplary embodiments, the elements of system 10may be coupled together with fluid couplings. One exemplary embodimentof such coupling 170 is shown in FIG. 17 coupling a component 40 to asecond prime mover 50. Fluid coupling 170 includes one or more hydraulicmotors/pumps 172 and a fluid channel 174 that couples together thehydraulic motors/pumps 172. While fluid couplings 170 may increase thecost of system 10, they allow greater flexibility in the placement ofthe various elements of system 10 over that which would be generallypossible if the elements are coupled with mechanical shafts.

It is also important to note that the arrangement of the hybrid drivesystem components, as shown, are illustrative only. Although only a fewembodiments of the present disclosure have been described in detail,those skilled in the art who review this disclosure will readilyappreciate that many modifications are possible (e.g., variations insizes, dimensions, structures, shapes and proportions of the variouselements, values of parameters, mounting arrangements, materials,colors, orientations, etc.) without materially departing from the novelteachings and advantages of the subject matter recited herein. Further,the discussions related to optional clutches apply to other embodimentsdescribed with respect to other Figures. For example, although an APU 80and optional clutches are shown in various embodiments, they can beremoved from the system without departing from the scope of theinvention unless specifically recited in the claims. Accordingly, allsuch modifications are intended to be included within the scope of thepresent disclosure as described herein. The order or sequence of anyprocess or method steps may be varied or re-sequenced according toalternative embodiments. Other substitutions, modifications, changes,and/or omissions may be made in the design, operating conditions andarrangement of the preferred and other exemplary embodiments withoutdeparting from the exemplary embodiments of the present disclosure asexpressed herein.

What is claimed is:
 1. A vehicle drive system for a vehicle comprising afirst prime mover, a first prime mover driven transmission, and a PTO,the vehicle drive system comprising: an electric motor coupled to thePTO for receiving power from the first prime mover through the PTO; ahydraulic pump in mechanical communication with the electric motor foroperating equipment or components, wherein the electric motor canreceive power from the first prime mover driven transmission through thePTO, wherein the hydraulic pump can receive power from the electricmotor when the electric motor rotates; a first energy source operable toprovide power to or be powered by the electric motor; and a clutchdisposed between the first prime mover driven transmission and theelectric motor, wherein when energy from the first energy source isbelow a threshold, the clutch is engaged, wherein the clutch isdisengaged when the hydraulic pump receives power from the electricmotor when the first prime mover is off, and wherein a speed of thefirst prime mover or the electric motor is adjusted prior to engagementof the clutch to ensure that input and output speed of the PTO match aratio of the PTO to allow continuous operation of the equipment orcomponents, thereby reducing abrupt changes in hydraulic pump speed,wherein the PTO is modified to allow a shaft connected to the PTO tospin with low resistance when the electric motor is rotated to power thehydraulic pump.
 2. The vehicle drive system of claim 1, wherein theequipment is comprised of at least one of an aerial bucket device, adigger derrick, and a compressor.
 3. The vehicle drive system of claim2, wherein the hydraulic pump powers at least one of the aerial bucketdevice, digger derrick, and compressor.
 4. The vehicle drive system ofclaim 1, wherein the equipment or components is comprised of at leastone of a compressor, a water pump, and a cement mixer drum, and theelectric motor provides power to the at least one of the compressor, thewater pump, and the cement mixer drum.
 5. The vehicle drive system ofclaim 1, wherein the electric motor is activated by a controller thatreceives a signal sent through at least one of fiber optics, pneumatics,and a wireless channel.
 6. The vehicle drive system of claim 1, whereinwhen there is insufficient energy to power the hydraulic pump solelythrough operation of the electric motor, the first prime mover isstarted and the clutch is engaged.
 7. The vehicle drive system of claim1, wherein rotational speed of the hydraulic pump is constant and outputof the hydraulic pump is varied to change flow.
 8. The vehicle drivesystem of claim 1, wherein another clutch is positioned between theelectric motor and the hydraulic pump.
 9. The vehicle drive system ofclaim 1, wherein the speed of the electric motor is varied to reduceflow from the hydraulic pump for two speed operation of an aerial deviceor a digger derrick.
 10. The vehicle drive system to of claim 1, whereinthe hydraulic pump continues to operate at the same rpm when the clutchis engaged and disengaged.
 11. A method of operating a vehicle drivesystem comprising a first prime mover, a first prime mover driventransmission, a second prime mover, a PTO operable to transfer powerfrom the first prime mover driven transmission to the second primemover, a first energy source operable to provide power to or be poweredby the second prime mover, the method comprising: powering an accessorythrough operation of the second prime mover; and engaging a clutchdisposed between the first prime mover and the second prime mover todrive the accessory via power from the first prime mover, wherein whenenergy from the first energy source is below a first threshold, thefirst prime mover is started and the clutch is engaged, wherein a speedof the first prime mover or the second prime mover is adjusted prior toengagement of the clutch to ensure that input and output speed of thePTO match a ratio of the PTO, wherein the accessory is a variable volumedisplacement pump and wherein the variable volume displacement pump isconfigured to operate continuously only providing flow if there is ademand, wherein when no demand is present, the variable volumedisplacement pump provides little or no additional friction orresistance.
 12. The method of claim 11, wherein the first prime moverpowers the second prime mover to power the first energy source while atthe same time the first prime mover powers the accessory.
 13. The methodof claim 11, wherein the clutch is subsequently disengaged when theenergy from the first energy source is above a second threshold.
 14. Themethod of claim 11, wherein the accessory continues to receive powerwhen power for the accessory is switched from the second prime mover tothe first prime mover.
 15. The method of claim 11, wherein if there isinsufficient energy to power the accessory solely through the operationof the second prime mover, the first prime mover is started and theclutch is engaged.
 16. The method of claim 11, further comprisingengaging or disengaging the PTO from the first prime mover driventransmission when portions of the vehicle drive system other than thefirst prime mover do not require or can be damaged by a connection tothe first prime mover.
 17. The method of claim 11, further comprising acontroller configured to charge the first energy source to a first levelby the operation of the first prime mover and to a second level using agrid, wherein the second level is greater than the first level.
 18. Themethod of claim 11, further comprising operating the first prime moverto simultaneously provide power to a drive shaft and operating thesecond prime mover through the first prime mover driven transmission.19. The method of claim 11, wherein the PTO is disengaged from thesecond prime mover during driving.
 20. A vehicle drive system for avehicle comprising a first prime mover, a first prime mover driventransmission, and a PTO, the vehicle drive system comprising: anelectric motor coupled to the PTO for receiving power from the firstprime mover through the PTO; a hydraulic pump in mechanicalcommunication with the electric motor for operating equipment orcomponents, wherein the electric motor can receive power from the firstprime mover driven transmission through the PTO, wherein the hydraulicpump can receive power from the electric motor when the electric motorrotates; and a clutch disposed between the first prime mover driventransmission and the electric motor, wherein the clutch is disengagedwhen the hydraulic pump receives power from the electric motor when thefirst prime mover is off, and wherein a speed of the first prime moveror the electric motor is adjusted prior to engagement of the clutch toensure that input and output speed of the PTO match a ratio of the PTOto allow continuous operation of the equipment or components, whereinthe PTO is configured to allow a shaft connected to the PTO to spin withlow resistance when the electric motor is rotated to power the hydraulicpump.
 21. A method of operating a hybrid vehicle drive system comprisinga first prime mover, a first prime mover driven transmission, a secondprime mover, a PTO component operable to transfer power from the firstprime mover driven transmission to the second prime mover, a firstenergy source operable to provide power to or be powered by the secondprime mover, the method comprising: powering an accessory throughoperation of the second prime mover; and engaging a clutch disposedbetween the first prime mover and the second prime mover to drive theaccessory via power from the first prime mover wherein a speed of thefirst prime mover or the second prime mover is adjusted prior toengagement of the clutch to ensure that input and output speed of thePTO component match a ratio of the PTO component, wherein the PTOcomponent is modified to allow a shaft connected to the PTO component tospin with low resistance when the second prime mover is rotated to powerthe accessory.
 22. A vehicle drive system for a vehicle comprising afirst prime mover, a first prime mover driven transmission, and a PTO,the vehicle drive system comprising: an electric motor coupled to thePTO configured to receive power from the first prime mover through thePTO; a hydraulic pump in mechanical communication with the electricmotor for operating equipment or components, wherein the electric motoris configured to receive power from the first prime mover driventransmission through the PTO, wherein the hydraulic pump can receivepower from the electric motor when the electric motor rotates; and aclutch disposed between the first prime mover driven transmission andthe electric motor, wherein the clutch is configured to be disengagedwhen the hydraulic pump receives power from the electric motor, andwherein a speed of the first prime mover or the electric motor isadjusted prior to engagement of the clutch to ensure that input andoutput speed of the PTO match a ratio of the PTO to allow continuousoperation of the equipment or components, wherein the PTO is configuredto allow a shaft connected to the PTO to spin with low resistance whenthe electric motor is rotated to power the hydraulic pump.
 23. A methodof operating a vehicle drive system comprising a first prime mover, afirst prime transmission, a second prime mover, a PTO configured totransfer power from the first prime transmission to the second primemover, a first energy source configured to provide power to or bepowered by the second prime mover, the method comprising: powering anaccessory through operation of the second prime mover; and engaging aclutch disposed between the first prime mover and the second prime moverto drive the accessory via power from the first prime mover, whereinwhen energy from the first energy source is below a first threshold, theclutch is engaged, wherein a speed of the first prime mover or thesecond prime mover is adjusted prior to engagement of the clutch toensure that input and output speed of the PTO match a ratio of the PTO,wherein the clutch is disengaged to allow a shaft connected to the PTOto spin with low resistance when the second prime mover is rotated topower the accessory using the energy from the first energy source.